In the prior art, liquid medicine, blood or the like is fed into a patient by means of a solution transfusion line or a blood transfusion line equipped with tubes. In such case, the connecting structure of a connector is adopted to connect various tubes that form the transfusion line or the like (for example, see Patent Reference 1). Said medical connecting unit (connecting structure of the connector) has a male connecting unit and a female connecting unit connected to the end portions of the tubes to be connected to each other.
The male connecting unit is composed of a connecting pipe having a luer tapered outer wall and an outer cap surrounding said connecting pipe. The female connecting unit is formed as a cylindrical body that can be inserted into the outer cap, and it allows fitting of the connecting pipe to its interior. Additionally, thread strips are formed on the inner wall of the outer cap, and thread strips that can be engaged with the thread strips of said outer cap are formed on the outer wall of the female connecting unit. As a result, while the connecting pipe is fit in the female connecting unit, the outer cap can be rotated so that the thread strips engage with each other and the male connecting unit and female connecting unit can be connected to each other; see [Patent Reference 1] Japanese Kokai Patent Application No. Hei 5[1993]-31180
However, the aforementioned medical connecting unit has some problems. If the thread strips are engaged too tightly with each other, cracks develop on the female connecting unit, leading to leakage of liquid. On the other hand, if they are engaged too loosely, the connection breaks, or the connection between the male connecting unit and the female connecting unit slackens, leading to generation of a gap between them and thus leakage of the liquid flowing inside.
The object of the present invention is to solve the aforementioned problems of the prior art by providing a connecting structure of a connector that can prevent cracks and leakage of liquid.